Electric incandescent lamp



Sept, 4, 1928. Q hfiszfiifi s. L. LEBBY ELECTRIC INCANDESCENT LAMP FiledJune 28, 1923 gwoentoz 524265 Lee Lebb y Patented Sept. 4, 1928.

UNITED STATES 1,682,916 PATENT OFFICE.

STATES LEE LEIBBY, OORNIN G, NEW YORK, ASSIGNOB TO OOBNING GLASS WORKS,OI CORNIN G, NEW YORK, A CORPORATION 01' NEW YORK.

ELECTRIC INCANDESOENT LAMP.

Application filed June 28, 1923. Serial No. 648,371.

This invention is an improvement in electric incandescent lampfilaments.

Its primary object is to provide a lamp for projection purpose having afilament composed of a plurality of arallel filament elements mounted soclose y together that the rojected images from each element overl p eachother, the arrangement of the filament supports being such thatnotwithstanding the proximity of the filament ele- -ments, arcingbetween them is prevented.

-In practice the lamp filament comprises a plurality of small bent orsubstantially U-shaped filament elements, wh1ch collectively form a highvoltage filament, the terminals of such e ements being so arranged as toprevent arcin and the elements are mounted side by si e and in parallelrelation to each other, and so closely together that the beams projectedfrom the several elements overlap each other, and thus com, bine to forma single powerful beam.

In the accompanying drawing which forms a part of this application, andm which like reference characters refer to like parts throughout theseveral views Figure 1 represents an elevational V18W of an electricincandescent lamp, apart of the bulb being in section, showing a sideview of the filament structure.

Figure 2 represents a perspective view of the filament structure, and

Figure 3 represents an enlarged plan view of the filament structure.

Referring to the drawings, the lamp comprises a globe which is providedwith a threaded base 11 of usual construction for fitting the lamp intosockets. tom of the base is a contact 12 that 1s connected with aleading-in wire 13, the contact'being insulated from the base 1n theusual manner, while to the upper part of the base is attached theextremity of a return wire 14.

Carried by the base in the usual manner,

I and projecting upwardly into the globe 10,

is a standard which is, as shown, composed of glass. The wires 13 and 14are embedded, in the standard and near the top thereof are joinedrespectively to a pair of upwardly extending posts 16 and 17.

Projecting upwardly from the center of the standard 15 between the posts16 and 17 is another post 18 that carries a glass insulating body 19.Extending upwardly from On the bot-' the body 19 is a pair of supports20 and 21,

the u per extremities of which are bent to provife a pair of horizontallimbs 22 and 23, res ectively.

As s own, the filament supports are so dlsposed that the limbs 22 and23, while parallel to each other, are so arran ed that the bend of thesupport 20 is direct y 0 pcsite the top of the post 16 on one side 0 theax1s of the lamp, andv on the other side of the axis the bend ofthesupport 21 is opposite-the top of the post 17. A filament 24 isconnected to the top of the post 16 and to the end of the limb 22.Another filament 25 is'connected to the bends of both of the supports 20and 21, and a third filament 26 is connected to the end of the limb 23and to the top of the post 17. The filaments thus mounted are side bside and in'parallel relation to each ot er, and so closely togetherthat the beams projected from the several filaments overlap each other,and

thus combine to form a sin 1e powerful beam. The filaments are rmed fromlengths of coiled filament wire, and by preference they are bent orsubstantially of inverted U shape as shown.

This construction is such that the current, on flowing u wardly throughthe post 16 is carried by the filament 24 to the end of the limb 22..The current then flows through the limb 22 to the bend of the suport 20,and across the filament 25 to the 11d of the su port 21. Continuingalong the length of t e limb 23, the current now flows across thefilament 26, and down the post 17 to the return wire 14.

When this construction is used in a 100 volt lamp the potentialdifierence between the top of the post 17 and the bend of theadjacentsupport 21 will be only 33 volts, while the potentialdifi'erence between the bend of the support 21 and the end of theadjacent limb 22 will be only 33 volts, and the potential differencebetween the top of the post 16 and the bend of the adjacent support 20will be only 33 volts. Thus despite the proximity of the filamentterminal there will be no danger of arcing between them.

For the purpose of retaining the filaments in roper relation to' eachother, I utilize a plurality of anchor wires 27, each of which consistsof a len h of stiff wire having one end embedded 1n the insulating body19, and its upper end provided with a U-shaped seat 28 tor the filament,such scat being formed by bending the outer end of the Wire, as shown.

Having thus described my invention, what I claim is 1. An electricincandescent lamp having a plurality of substantially U-shaped filamentseach formed of a length of coiled filament wire and mounted in parallelplanes, the adjacent terminals supporting the filaments having the samepotential difference between them as the voltage drop in a singlefilament element.

2. An electric incandescent lamp having a plurality of substantiallyU-shaped filaments relatively short in length and formed of coiled wireand mounted close together in parallel planes, the voltage drop betweenadjacent filament ends not exceeding the voltage drop due to a singlefilament element.

3. An electric incandescent lamp having a plurality of parallelfilaments formed of short lengths of coiled filament wire and arrangedclose together and electrically conneeted in series, and nonlumino'usconnections electrically connecting the ends of the filaments in such amanner that the positive ends of the filament are arranged at one sideand the negative ends at the otherrside of the lamp.

4. An electric incandescent lamp having a plurality of parallelsubstantially short U- shaped coiled filaments arranged close togetherand electrically connected in series,

and nonluminous connections electrically connecting the filaments insuch a manner that the current flows through all the filaments in thesame direction.

5. An electric incandescent lamp having a pair of filament supports, theupper ends of which are bent in opposite direction to providesubstantiallly parallel limbs arranged close together, a pair of poststo which the leading-in Wires are connected, one post terminating at itstop opposite the bend of one support and the other post terminating atits top opposite the bend of the other 6. An electric incandescent lamphaving a pair of filament supports terminating in parallel limbsarranged close together, a pair of posts to which the lead-in wires areconnected, one post terminating at its top oppo site the end of one limband the other post terminating at its top opposite the opposite end ofthe other limb, a relatively short coiled filamentconnected at its endsadjacent the opposite ends of said limbs, and relatively short coiledfilaments substantiall parallel with and close to the first namefilament and respectively connecting the tops of the posts with theremote ends of said limbs.

In testimony whereof I hereunto afiix my signature.

STATES LEE LEBBY.

